On Tue, Jun 14, 2011 at 06:30:19PM +0100, Lorenzo Pieralisi wrote:> On Mon, Jun 13, 2011 at 07:20:34PM +0100, Colin Cross wrote:>> According to the PL310 TRM (r3p2 3-9) on disable the PL310 syncs, which means> it flushes internal buffers, but it is not supposed to clean dirty lines.> It seems unsafe to me to use the stack and other cacheable data right before> disabling.> > > Otherwise, wouldn't a flush_cache_all() and l2x0_flush_all() in> > l2x0_disable() ensure the stack lines were flushed out? Probably> > needs a readl_releaxed as well, to ensure the disable has taken> > effect.> > > > I reckon the safest option is to clean and disable in one C> function. Moreover at that point in time spinlocks might not be an option> anymore (CPU out of coherency), which makes those functions unusable.

I was planning to add this functionality as part of my kexec patches sinceotherwise the l2x0_lock gets blown away on disable. I initially attributedthis to loss of coherency, but that's clearly not the case as I still had L1running.